Sasooli's incorrect. This is an auto-win with Mindslaver because a player doesn't lose the game for having zero or less life until Game of Chaos finishes resolving. State-based actions are not checked mid-resolution.

Just keep going until the stakes are lethal, and then keep going until your opponent loses a flip. You'll gain back enough life to keep you alive, and they'll lose enough to die. Then end the spell's resolution and win the game. Because 1 + 2 + 4 + 8 + ... + N is still less than 2N, a single coin-flip win for you is enough to guarantee swinging your entire life total into the positive and theirs into the negative (when N is large enough).

This is also why the loser logically cannot be the one to choose to continue flipping -- if they could, the loser would always choose to flip again, so the spell would never stop resolving.

This could trigger Ajani Pridemate quite a few times. Kavu Predator would probably be better, but there's gotta be something breakable in that idea. It is life-loss/life-gain, though, so it isn't exactly like Mana Clash.

No matter what, it costs you a card. Therefore, a smart opponent is going to want to end the flips as soon as possible -- if this card does almost nothing, they come out ahead. If you lose the first flip? They'll end it immediately and laugh in your face for wasting a card to give them a bit of your life. And the chance that you'll win both the first two flips is only 25%, meaning that against a smart opponent, this card will lose you one or two life most of the time, and do nothing else.

For it to really be worthwhile, you have to win on the third or later flip -- and (again, remembering that your opponent is probably going to shut things down early if they win), you have only a 12.5% chance of getting to that point.

Just play a direct damage spell, for heaven's sakes.

(Krark's Thumb helps a lot, but you still only have a 42% chance of winning three times in a row; there are better things you... (see all)